Thank you for your input, we are looking into the problem.
“http://download.eclipse.org/tools/pdt/updates/” is meant to be used through the eclipse update manager, and it works. You get the 404 message when opening it from the browser.
As for the mirrors not working – it is eclipse policy not to mirror Nightly and Integration builds. Since our project is still in the Incubation phase, most of our builds are still integration builds.

This means I cannot install the PDT plugin on a fresh Eclipse install. Personally for me PDT downloads have *always* been hectic for the last 6 monthes. Eclipse mirrors don't work, today even the official site is down.

You should really attempt to fix that as I believe it is hurting the project.